Dual Energy Radiography versus Quantitative Computer Tomography for the Diagnosis of Osteoporosis

Abstract

In this study we compared dual energy radiography (DER), a new, highly precise x-ray densitometric technique recently devised for measurements of vertebral mineral density and quantitative computer tomography (QCT), a densitometric technique that selectively measures the trabecular compartment of the vertebra. DER and QCT measurements were obtained in 56 healthy (H) and 48 fractured osteoporotic (OP) women using a Hologic QDR 1000 bone densitometer and a GE 9800 scanner, respectively. DER was significantly correlated with QCT in both the H (r = 0.75; P less than 0.0001) and the OP subjects (r = 0.58; P less than 0.0001). DER decreased significantly with age in the H (P less than 0.05), but not in the OP women, whereas QCT was related to age in both the H (P less than 0.0001) and the OP subjects (P less than 0.01). The rate of bone loss with age was also higher with QCT than with DER in both normal and osteoporotic women. The difference in bone density between the H and the OP subjects was larger (P less than 0.05) with QCT than with DER. Receiver operating characteristic analysis revealed that QCT was a better predictor of vertebral fractures than DER. A larger percentage of OP subjects were 2 SD or more below the normal predicted value with QCT (41%) than with DER (29%). Furthermore, the slopes of the regressions of bone density with age for normal and osteoporotic women were significantly different (P less than 0.05) with QCT but not with DER. These findings are consistent with a disproportionate loss of trabecular bone with age in osteoporosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Cementless total hip replacement does not change bone mineral density of the lumbar spine DEXA measurements in 50 patients

“…The maximum difference in bone density between single measurements was -1.0% to +0.5%. Taking into account the coefficient of variation and precision of the DEXA method, which was determined at 1% in vivo in our own studies and between 0.6% and 2.1% in the literature, the measured differences in BMD lie within this coefficient of variation (Mazess et al 1989, Pacifici et al 1990, Sartoris and Resnick 1990, Semler 1992. Moreover, no significant differences could be found between the changes in men's and women's BMD-levels.…”

Dual-energy X-ray absorptiometry overestimates bone mineral density of the lumbar spine in persons with spinal cord injury

“…13 Indeed, in the general population qCT seems to be a more sensitive technique for the diagnosis of osteopenia and to correlate better with fracture risk than that of DXA. 21,22 However, qCT is not the method of choice for monitoring serial changes in BMD owing to its inferior precision, relatively high radiation exposure, more difficult positioning, longer duration of scan and higher cost than DXA. 23,24 Of note, a correlation was shown between L-spine BMD by qCT and level of lesion.…”

Application of quantitative computed tomography for assessment of trabecular bone mineral density, microarchitecture and mechanical property

“…A faster decline in BMD with aging was found in the QCT thoracic than the DXA lumbar and femoral neck measurement. The conclusion is clear that the QCT is a more sensitive method for detecting the bone density change in comparing with the DXA [22,88,91,93,94].…”

“…Studies for predicting fracture were reported [77,94,100,101]. The FRAX 10-year fracture risk calculation tool was established by Kanis et al using the hip DXA [71].…”

“…The comparative study of QCT and DXA was also completed. The results indicated that the QCT is a more sensitive method to predict the fracture risk [77,94,100,101]. An advanced investigation, just like DXA, was necessary to develop a model for assessing the fracture possibility in the spine or hip by using relative factors, which include the BMD, microarchitectural and mechanical data from QCT assessment, and important clinical applications.…”